[Determination of ligustrazine in human plasma by high performance liquid chromatography with solid-phase extraction]

A high performance liquid chromatographic method was developed for the determination of ligustrazine in human plasma. The chromatographic separation was performed on a Luna C18 column (150 mm x 4.6 mm i.d., 5 microm) at column temperature of 40 degrees C. The mobile phase, a mixture of methanol-acetonitrile-acetate buffer of pH 5.0 (50:8:42, v/v), was delivered at a flow rate of 1.0 mL/min. The detection wavelength was 280 nm. Plasma samples were prepared with a C8 solid-phase extraction column. Linearity was confirmed in the mass concentration range of 25-5000 microg/L with the correlation coefficient of 0.9999. The extraction recovery of ligustrazine ranged from 96.72% to 100.90%. The relative standard deviations (RSDs) of intra- and inter-day assay at the mass concentrations of 50, 500 and 3000 microg/L were less than 8.64% and the accuracies were between 99.59%-103.26%. The limit of detection (LOD) was 10 microg/L. The results of this method validation satisfactorily meet the acceptance criteria of bioanalysis and the method is applicable to the pharmacokinetic studies of ligustrazine in human beings.